A heap buffer overflow vulnerability was found in Apple’s XNU OS kernels by Kevin Backhouse. An exploit can potentially cause any iOS or macOS device on the same network to reboot, without any user interaction. Apple has classified this kernel vulnerability as a remote code execution (RCE) vulnerability in the kernel. It may be possible to exploit buffer overflow to execute arbitrary code in the kernel.

The vulnerability is caused by a heap buffer overflow in the networking code within the XNU kernel. XNU is a kernel system developed by Apple. It is used in both iOS and macOS, hence most iPhones, iPads, and Macbooks are affected.

An attacker merely needs to send a malicious IP packet the target device’s IP address to trigger this. The vulnerability is triggered only if the attacker is in the same network as the target. This becomes easy if you’re using a free WiFi network from a coffee shop. The vulnerability being in the kernel, anti-viruses cannot protect your device.

The attacker can control the size and content of the heap buffer giving a potential to gain remote code execution of a device.